The AIDS epidemic in West Africa is complicated by the presence of a second immunodeficiency virus, HIV-2. We have demonstrated a long latency period to clinical disease in cohort of HIV-2 infected women in Senegal; but the full dynamics of the natural history and disease manifestation of HIV-2 need to illucidated. Only then can one project the future impact of the retroviral infection for either the individual or the population exposed. We are proposing to conduct hospital-based studies among adults in Dakar, Senegal. SPECIFIC AIMS: 1) To evaluate the degree of disease association with retroviral exposure to either HIV-1, HIV-2 or both. To evaluate the utility of AIDS surveillance in adults in this region for these viruses. 2) To evaluate the clinical manifestations of HIV-1 and HIV-2 associated disease in this population and to search for possible new or unexpected clinical associations with HIV-2 infection. 3) To determine the clinical outcome and the approximate mean survival time of HIV-2 associated AIDS. To be able to compare this survival time to the survival times of HIV-1 associated AIDS and of seronegative patients with similar initial clinical presentations. 4) To determine the clinical and immunological alterations of HIV-2 related disease and their potential role as prognostic markers in the course of retroviral disease in a West African region. 5) To evaluate patients of varying stages of clinical disease to attempt to identify "variants" or "serotypes" of HIV-2, differing in pathogenic potential.